Amanda Seyfried has opened up about her lengthy battle to get her obsessive-compulsive disorder under control.

“I’m on Lexapro, and I’ll never get off it,” Seyfried, 30, told Allure of her condition. “I’ve been on it since I was 19, so 11 years. I’m on the lowest dose. I don’t see the point of getting off it. Whether it’s placebo or not, I don’t want to risk it.”

Seyfried, who is engaged to actor Thomas Sadoski, says mental illness should be taken as seriously as any physical ailment. “You don’t see the mental illness: It’s not a mass; it’s not a cyst,” she explained. “But it’s there. Why do you need to prove it? If you can treat it, you treat it.”

She says her OCD brought on health anxiety, which she’s had to get under control, too. “I had pretty bad health anxiety that came from the OCD and thought I had a tumor in my brain,” she recalled. “I had an MRI, and the neurologist referred me to a psychiatrist.”

Today, things are going much better for the “Big Love” alumna. “As I get older, the compulsive thoughts and fears have diminished a lot,” Seyfried said. “Knowing that a lot of my fears are not reality-based really helps.”

Seyfried hasn’t been shy about seeing a therapist. “[Therapy] is coping with life,” she told Marie Claire UK in 2015. “I just think, ‘You go to the doctor about heart problems, or an eye doctor if you have an infection.’ You have to take care of yourself.”